Posts Tagged ‘groundwater’

The Airport is located quite far from the city, about 30 kilometres away. It is too far away from city lines and has to depend on groundwater. It needs 9 million litres per day eventually though for now 5 million litres per day will do. To boot it is located in what was called a ‘dark zone’ by the Central Ground Water Board, meaning groundwater was being exploited beyond recharge potential. An Airport needs water and plenty of it. So what did it do?

For one it requested and sourced fresh water from the city paying Rs 66 a kilo-litre, a high price which gave the water utility supplying it some monies. This fresh water is limited to about 1.5 million litres daily. It then did a smarter thing, it bought tertiary treated waste-water and a full 2 million litres of it daily and it paid Rs 25 a kilo-litre for this treated waste-water. This was separately stored and used for the vast beautiful landscape springing around, a huge bio-diversity of plants and even a small wetland.

For the internal waste-water generated it set up its own sewage treatment plant using extended aeration system. This treated water is then reused for flushing the toilets in the airport premises as well as for the air cooling systems. The sludge generated from the sewage treatment plant is composted and reused as manure for the landscaped area.

An internal waste-water treatment plants treats all waste-water as well as waste from aeroplanes

Runways and the area surrounding it generate large quantities of storm water when it rains. It is therefore very important that this run-off be collected and quickly disposed off and flooding avoided. With more than 310 recharge wells located in the storm water drain or immediately adjacent to it a large volume of the rain is recharged into the aquifer. Well designed storm-water drains then take away the rest of the rainwater to an adjacent lake which is capable of receiving this large flow of rain.

Two things have happened due to these good efforts. Four large open wells which were old existing constructions have been rehabilitated, cleaned up and repaired. Pumps and a filter have been attached and the water quality tested. It is found that this is very high quality, sweet potable water. Thanks to the recharge efforts the wells stay full even during summer. Up-to 800,000 litres of water can be drawn from these open wells daily and in an emergency they can replace the mains water from the city. A landscape which was once a dark zone, given a holiday for high extraction from bore-wells and with enough recharging can be revived to such an extent that open wells can have water.

Recharge of rainwater has helped aquifers rejuvenate with fresh clean water

From the airport buildings rainwater is stored in large underground sump tanks of about 1.5 million litres capacity and reused after treating. Excess water from the sump tanks is then allowed to flow into storm drains and recharge the aquifer as well as flow into the adjacent lake.

The revival of the adjacent lake also means that villages and towns adjacent to the airport, such as the town of Devanahalli, can now think of sourcing groundwater from adjacent to the lake to fulfill the towns water requirements.

Sludge drying beds

Economic activity and service activity like airports are essential for economic growth and to spur the progress of a city. Instead of seeing it as placing demand on water services through innovative design they can absorb waste-water from cities and be able to use it to meet its requirements. Through waste-water treatment and reuse and through rainwater harvesting groundwater aquifers can be revived and lakes kept full. These can then be of great help to surrounding communities. The Kempegowda International Airport at Bangalore showcases just that. This is water wisdom.

It is a comprehensive win for a model of development now likely to replicate itself in many other states all across India. What could be some of the characteristics of this development strategy ? Clearly it will be an infrastructure led model.

Electricity and the power sector: This is one sector where the Gujarat model is striking and clearly ready for a roll out. Segregating the rural agriculture sector from habitations, ensuring 24 hours supply to homes and then ensuring 8 hours of reliable and robust power to the agriculture sector will not only help farmers but also boost the growth in this area substantially. Urban power supply without any power cut is something almost every household and industry looks forward to. Alternative energy such as solar and wind energy should also get a substantial boost.

Water: While river inter-linking may have been the rhetoric it is likely that the focus would be back on major irrigation and groundwater. While water for irrigation should get a ramping up in terms of outlay and investments, greater focus will be on increasing efficiency of delivery through canal lining, improved governance et al. Also like the massive Saurashtra model of water harvesting, using soil and water conservation measures at large scale in a partnership with communities will help the groundwater sustainability and availability. India’s dependence on groundwater cannot be overemphasized and this sector will see much attention in the coming years.

In urban areas the Surat model of water and sanitation with an overall goal of 24/7 water supply and full underground sewerage system with waste-water treatment and recycling will roll out all across Indian cities. Rural sanitation should get a solid boost with it having the personal attention of the Prime Minister.

Transport: The Bus Rapid Transport System (BRTS) of Ahmedabad is a model for the rest of the country. For sure mass transportation including metro rail and BRTS will to overcome the gridlock in urban India will be the direction. Atal Behari Vajpayee ‘s National Highway Grid and the Pradhan Mantri Gram Sadak Yojana , both hugely successful initiatives, should see increased focus for finance. It is through this investment that every village in India can be touched and linked to the overall development of the nation.

Housing: This will be a tough sector to deal with and it is not clear how the path ahead lies because there is no Gujarat model to follow here. However it is clear that the private sector will play a much more important role than previously and land reforms in urban areas will take priority.

The policy imperative will demand that a National Energy Policy, a National Water Policy within which an Urban Water and Sanitation Policy and a Groundwater Policy is included and a National Transportation Policy, including roads and railways, amongst many others be articulated to indicate the direction in which the government will move in the coming years.

It is a strange place to have placed four towers and have started a city but perhaps Magadi Kempegowda was not thinking of water when he had his grand dream. The city now has outgrown those four towers and the one small stream which was the only part of a running water landscape is now desecrated beyond measure and called the Vishabhavati (the poison river) from the original Vrishbhavati (that which originates from the mouth of a bull) .

As early as the 1850’s the British were complaining about the water and sanitation systems. It also did not help matters that sewage was being left into the very source from where water was being drawn. Both Ulsoor and Dharmambudhi Lake being the source and the sink.

In a pioneering effort of its kind, most probably aided by the fact that this was city not near a perennial water source and there was always a sense of shortage, the city started to search for water from far. Hessarghatta on the Arkavathy reservoir 24 km away was first developed as a storage dam. Steam engines were used to pump water into the city and when electricity came that then replaced the steam engines. In each case Bangalore was a pioneer in the use of steam and electricity to pump water to itself. Hessarghatta was found short to slake the cities thirst and Thippagondanahally on the junction of the Kumudvathi and Arkavathy came into being as a new reservoir in addition to the Arkavathy in the mid 30’s. The city continued to grow and in the 1970’s the Cauvery was tapped at Torekadinahalli, pumped to a distance of 95 kilometres and 300 metres high to quench the city’s thirst. This was a remarkable engineering feat by a remarkable institution the Bangalore Water Supply and Sewerage Board- BWSSB – the first exclusive city level water and sanitation utility created in India. Stages 1, 2, 3 and 4 and phases 1 and 2 of stage 4 have kicked in and one of the costliest water in Asia comes after being pumped in three stages into the city. Alas the limit to drawal also has been reached and there is no more water for the city unless there is a redrawing of the water requirement between the irrigation and the urban sector in the Cauvery basin part of Karnataka.

In the meantime the city found out an uncomfortable truth, not all of it was in the Cauvery basin. In fact 2/3rds of it was outside the basin and in a river called the Dakshina Pinakini or the Ponnaiyar so that part was not entitled to water from the Cauvery basin or so said the tribunal.

In true government style a committee was formed to find out how the growing needs of the economic and domestic demand of the city could be met. Proposals include getting water from the Hemavathi, the Sharavathy as well as the west flowing rivers. These of course are huge projects involving lots of money and energy, something which should get the construction lobby salivating.

In the meantime there are practical proposals such as rooftop rainwater harvesting, the rejuvenation of the remaining lakes of the city, the recharging and the management of the groundwater in the city and most importantly the treatment and reuse of waste-water which show tremendous opportunities.

While the city gets 1400 million litres of piped water supply, the equivalent of 3000 million litres per day falls as rain on it. The total volume of wastewater available for reuse is 1100 million litres and the amount of groundwater that can be drawn sustainably is close to 600 million litres per day provided it is adequately recharged.

Do the math then

Average demand 200 Litres per capita per day

Total; available water

From Cauvery 1400 million litres per day

From groundwater 600 million litres per day

From recycled waste-water 1100 million litres per day

From rainwater 600 million litres per day ( 20 % rain harvested)

Total 3700 million litres per day

Good enough for a population of 18.50 million

…and if we get demand efficiency right and demand down to 100 litres per dapita per day

37 million people of Bangalore can be served ( current population 9 million)

Unfortunately the institution in charge of water supply is not completely geared to undertake a water management approach. It has no skill set for example in lake management or in hydro-geology.

If institutional capacities are built up, if there is a strong vision and an accountable authority created Bangalore in its pioneering way can overcome its water shortage problems. Else it will be forever condemned to become dependent on a tanker economy. The choice is ours and the time is now.

At first glance you see a protective fence which is not impressive but as you approach the magnificence of the structure strikes you , a beautiful 120 feet diameter open well full of water and you wonder whether this is the Bangalore where groundwater is supposed to have sunk to 1250 feet. This residential layout on the South of the city has done a magnificent job of managing its water purely through community action. A dynamic association has taken charge and the committed team first cleaned up the ‘Rajakaluve’- the main stream linking water above and beyond , passing through the layout. Its attention was then focused on the beautiful heritage well on campus. The well was cleaned and a 100 truck loads of silt removed. The silt was place in the gardens and the open spaces rich in fertile soil.

A beautiful old well revived and recharged – full of water

The well now becomes a supplemental source of water for non-potable use and in case of an emergency with treatment for all uses. Each house in the layout has been encouraged to go in for rainwater harvesting. In the storm drains which run around, all of them are maintained clean and percolation wells are being placed so that the road run-off is recharged into the ground. Ultimately all run-off will be sent into the aquifer with the site becoming a zero discharge area for storm-water.

A waste water treatment plant hums daily, treating and cleaning 200,000 litres of sewage from the entire colony. This treated waste-water too is reused in the layout. A 100 trees are planted every year and the waste water is used to feed the trees and the parks.

The community building where the residents meet , collects every drop of rainwater falling on the roof in large rain barrels and reuses them.

Rainwater Barrels collect rooftop rain

On the day one visited the campus children had gathered at a science fair and were demonstrating various experiments that they had set up. Most of them centred around water. A group of them had already been taken for a tour of the layout explaining what was happening with water and the necessity to keep the roads and storm water drains clean as well as to take care of the trees for the birds that are around.

A turtle was spotted in the well and was swimming about merrily, a cause for some excitement.

When communities come together it is possible to achieve the unthinkable, that is a clean environment and plenty of water with a bit of heritage thrown in. The more we expand thisn space the better for our urban areas. In this community awareness and action lies water wisdom.

Summary: It is in years of plenty that we should stock up for times of shortage

Many people are moving into a problem solving mode but it needs institutional reinforcement to help achieve maximum benefits.

The major Public Sector undertaking has a very large campus and has a huge water demand. It draws water from the Bangalore Water Supply and Sewerage Board and pays a hefty Rs 60 per kilo-litre for the water. Being water smart, it has set-up a waste-water recycling unit and ensures that all waste-water is treated and reused for non-potable purpose particularly gardening .Lawns are extensive in the campus and is needed for dust suppression. The unit has also set up a huge lake to harvest run-off from its vast land. More than 170 million litres of storm-runoff is stored in this vast lake.

Their attention has turned to the large rooftop areas they have on campus. From 11,500 square metre of roof area, they simply connected the rainwater downpipes and brought it into a small 20,000 litre sump tank. From here they have put a pump to send the water directly into a much larger sump tank which takes water through a Reverse Osmosis unit. This R.O. water is needed for their manufacturing purpose. The investment they had to make was Rs 10 lakhs. Was the investment worth it?

The benefits translate as follows. They are likely to harvest 10 million litres of water annually. This will result in a savings of Rs 6 lakhs annually. The payback period for the investment is thus less than 2 years. There are other benefits. The embodied energy in alternate water, either from the BWSSB or bore-wells, is roughly 2 units of power per kilo-litre of water. The industry will therefore save nearly 20,000 units of power annually. This also translates as a savings in carbon emissions.

There are other benefits. The harvested rainwater is very soft with a Total Dissolved Solids of less than 50 ppm. This is likely to reduce further as the initial leaching of cement from the sump tank and the pipes become less. As against this the water they used from bore-wells had a TDS level of nearly 1000 ppm. The life of the membrane used for R.O. now increases. The reject water from the R.O. has fewer salts and can be recycled more easily than before.

The advantage is clear and it is likely that the industry will move quickly ahead to cover all roof-tops with rainwater harvesting systems. This means that over 100,000 square metres can be covered and over 100 million litres of rainwater harvested. No small feat for an industry located in a water scarce city.

A University: The University of Agriculture with a sprawling 1200 acres campus was once outside the city. Now it has become integral and falls within the Corporation Limits. Its water demand for agricultural crops is high. Most of the water comes from bore-wells. These are over exploited and many have gone dry. It has designed for itself a watershed based rainwater harvesting system. Thanks to a bountiful September rain a great amount of water has been collected and allowed to percolate into the ground. Many bore-wells have revived and are humming with water. The University is able to meet its water demands and students and Professors can continue to develop knowledge with experiments on the ground.

Groundwater banks are being created in the city by institutions that occupy large tracts of lands and have large rooftops. These efforts supplement the water delivery to the city and make the city water smart. Things have to be scaled up and more such institutions brought into the rainwater harvesting community. Further deeper understanding of how much water is actually recharged into the ground, what is a reasonable water demand to keep the groundwater banks humming for 2 to 3 years will ensure that the water shortfall in the city is overcome. Creative solutions using knowledge is the hall mark of the city and in this lies water wisdom.

Well digging has been the forte of the ‘Mannu Vaddar’ community in Bangalore. They are the people who work with earth for many centuries. They have dug the many lakes of Bangalore and also the many wells that dotted the landscape. Then their cousins the ‘Kallu Vaddars’ would take over and line the well with stones . The craft is at least 6000 years old in India.

The stone lined wells of South Karnataka

Since the 1980 ‘s , especially during a period of 3 continuous years of bad rainfall, the construction of wells stopped and people shifted to the bore-wells. This rendered the well diggers jobless and they shifted to digging foundations for buildings as well as digging pits for toilets.

With the recent rainwater harvesting interest in the city and the coming in of the bye-law , wells are being dug again, only this time to recharge water from the rooftops and from storm water drains.

Muniyappa – is now known as ‘Bhavi’ Muniyappa or Well Muniyappa in Bangalore

People like Muniyappa have dug more than 2000 recharge wells . He is a legend in the community. Of course strong competition has cropped up and there are many more well diggers in Bangalore.

A good policy , such as the rainwater harvesting policy , introduced in Bangalore not only works for ecological benefits such as increasing the groundwater table , preventing floods , supplementing the water needs of citizens but also provides social benefits such as work to many well diggers. This is truly the ‘green economy’ kicking in and traditional crafts being revived.

Even though the well mentioned by Mr Balsubramanian is more than 30 years old he still remembers Arumugham who dug it for him, everyday he says.

The memory of the well is crucial to Bangalore. On groundwater will depend the city s future. Well diggers and the recharge wells they dig will become the water warriors of the city. Time to salute ’em.

This large beautiful well is close to Jakkur Tank in the Northern part of the city . The farmer draws 50,000 litres from the open well over a 12 hour time frame. Another 50,000 litres is drawn from a bore-well which is drilled inside the open well. This magnificent structure is about 50 years old. It is fed by the large Jakkur Lake with a 50 Hectare waterspread. The tank itself is designed to receive an eventual 10 million litres per day of treated waste water which should keep the lake full for the whole year. This well too will be full . Can we preserve and integrate the well into the water plans of the city ?